Method of tanning and dyeing furs and leather



Patented Nov. 15, 1927.

UNITED STATES PATENT OFFICE.

ANNIE PFEIFER, F RUMBURG, CZEGHOSLOVAKIA.

METHOD OF TANNING AND DYEING FURS AND LEATHER.

No Drawing. Application filed January 13, 1927, Serial No. 161,027, and in Germany and Czechoslovakia November 30, 1926.

, Hitherto and dyeing of furs and leather was only effected by cold methods. The methods used for this purpose (soaking, beating, spraying methods, etc.) are. however, extremely inconvenient and tedious and necessitate by reason of ti :dious treatment of each skin the greatest attention and skill by the operator, so that for this purpose only skilled workers can be employed. The cold dyeing of furs and a leather which was the only one hitherto usual, however, not only requires a considerable amount but is also expensive; also for this slow and weak-acting cold dyeing method the use of aniline dyes, particularly the indanthrene dyes which are fast against light and washing could not hitherto produce such a light and fire of the dye action as is obtained in textile fabrics in the textures.

A hot or boiling treatment of furs and leather when dyeing has not been effected hitherto as the leather of the fur cannot be treated hot according to the present tanning method if .it is to remain soft and pliable. As is well known the leather. when treated in a hot or boiling liquid. loses a large portion of its albumen and glue. because it is hard and loses life so that the whole pelt becomes useless. Contrary thereto the present invention permits, by a separate preliminary treatment, of a hot, even boiling, treatment of 6 furs and leather, mostly for many hours, 3

in a short time, as a rule in two hours. have been dyed completely :tadeless and of true colour and in fire and shading of the dye action far excels that previously obtained.

The invention consists of four main methods which follow one another at predetermined intervals:

1. A preliminary tanning of the skin with loam and common salt in water at a temperature of about 15 to 20 centigrade.

2. A gradually increasing alum tanning with common salt and alum at an increased temperature up to about 25 centigrade.

3. A gradually increasing chrome tanning with chrome alum up to about 15 to 25 centigrade.

The said means are themselves known tanwhen dyeing with the result that the goods;

ning agents. The tanning is followed by the usual removal of grease, drying and purifying of the skins. The skins thus preliminarily treated are ready for the hot dyeing and are capable of withstanding boiling when dyeing for a long time.

4. A boiling process commencing at 40 to 60 centigrade and increasing to 80, 90 centigrade and more.

After the boiling process the skins and the leather are rinsed and dried in the usual manner.

The new multi-step boiling and tanning process can be carried out by unskilled workers.

Claims:

1. The process of tanning and dyeing furs and hides. which consists in subjecting the furs or hides successively at predetermined intervals to a tanning with loam and common salt, a tanning with common salt and alum, and a tanning with chrome alum and thereupon a hot treatment with the usual dyes in the succeeding dyeing process.

2. The process of tanning and dyeing furs and hides. which consists in subjecting the furs or hides first to a tanning with loam and common salt at a temperature of approximately 15 to 20 centigrade, then to a tanning with common salt and alum at a temperature of approximately 25 centigrade, then to a tanning with chrome alum at a temperature of approximately 15 to 25 centigrade, and finally to a hot treatment with dyes.

3. The process of preparing furs and leather for hot treatment while dyeing, which consists in first subjecting them to a preliminary treatment with loam and cooking salt. and then to a tanning with alum followed by one with chrome. whereby the treated materials are rendered capable of withstanding a hot or boiling treatment with common dye-stuffs in the supplementary dyeing process at temperatures from about to 90 centigrade and over.

4. The process of preparing furs and leather for hot treatment while dyeing,

which consists in first subjecting them to a preliminary treatment with loam and cooking salt, and then to a tanning with alum with chrome, whereby the followed by one and the alum tanning with alum and cooking salt at a gradually increasing temperature up to 25 Centigrade, the chrome tan- 10 ning with chrome-alum at a gradually increasingtemperature of from 15 to 25 Centigrade.

VINCENZ 'ZETTLITZ. 

